It is desirable to make a board-to-board connector adaptable to high speed signal transmission, where the board-to-board connector is mounted in the smartphone and is for connecting a mother board and another board in the smartphone.
High speed signal transmission in a connector tends to increase EMI (electro-magnetic interference) noise emitted from a connection section between signal contact elements of the connector. The board-to-board connector adaptable to high speed signal transmission needs to be capable of shielding the EMI noise.
Conventional board-to-board connectors for smartphones, which have a lower height, e.g. about 0.6 to 0.7 mm, are not provided with an electromagnetic interference shield. On the other hand, conventional board-to-board connectors for computers or televisions are provided with an electromagnetic interference shield. However, since these board-to-board connectors with an electromagnetic interference shield have a height considerably larger than that of the board-to-board connectors for smartphones, it may be impossible to apply the structure of conventional board-to-board connectors with an electromagnetic interference shield to the board-to-board connectors for smartphones.
In addition, conventional board-to-board connectors with an electromagnetic interference shield have a structure in which only either one of a plug and a receptacle comprises the shield which is configured to surround both a plug housing and a receptacle housing when the plug has been inserted into the receptacle. These conventional board-to-board connectors cannot completely shield EMI noise. For example, in conventional board-to-board connectors with an electromagnetic interference shield, EMI noise may leak out by passing through a gap between the exterior of the plug housing and the interior of the receptacle housing and through the plug housing and the receptacle housing made of resin.
Japanese Unexamined Patent Application, First Publication No. 2012-54173 discloses a board-to-board connector comprising a plug and a receptacle which is fittable to the plug, wherein the plug comprises an insulation plug housing and a plurality of plug shield members which are fixed to the plug housing, and the receptacle comprises an insulation receptacle housing and a plurality of receptacle shield members which are fixed to the receptacle housing, and wherein ground contact portions extending from the plug shield members are respectively in direct contact with ground contact portions extending from the plug shield members. However, the plug shield members as well as the receptacle shield members are aligned in the longitudinal direction of the connector, but they are not provided on the opposite ends in the longitudinal direction of the connector, that is, the short side section of the periphery of the connector. Therefore, EMI noise may leak out by passing through the opposite end portions of the plug housing and the receptacle housing, which are positioned at the opposite ends. Furthermore, since there is a gap between the plug shield members and the receptacle shield members, EMI noise may leak out by passing through the gap.
Japanese Unexamined Patent Application, First Publication No. 2010-97759 discloses a board-to-board connector comprising a receptacle and a plug, wherein the receptacle comprises an insulation stationary housing, a movable housing which is provided on the stationary housing, a first shield cover surrounding the exterior of the stationary housing, and a second shield cover surrounding the exterior of the movable housing, and the plug comprises an insulation plug housing configured to be insertable into the movable housing and a plug shield cover surrounding the exterior of the plug housing. The second shield cover is provided with a plurality of bending tabs which are in direct contact with the plug shield cover when the plug has been fitted to the receptacle. However, the bending tabs are provided on the short side section of the periphery of the connector, but they are not provided on the long side section of the periphery of the connector. Therefore, EMI noise may leak out by passing through a gap between the long side section of the plug shield cover and the long side section of the movable housing and through the long side section of the movable housing.
Japanese Unexamined Patent Application, First Publication No. 2008-243703 discloses a board-to-board connector comprising a receptacle and a plug, wherein the receptacle comprises an insulation receptacle housing and a receptacle shield member surrounding an exterior of the receptacle housing, and the plug comprises an insulation plug housing and plug shield members covering the opposite ends of the plug housing. The receptacle shield member is provided with a plurality of bending tabs which are in direct contact with the plug shield members when the plug has been fitted to the receptacle. However, the bending tabs are provided on the short side section of the periphery of the connector, but they are not provided on the long side section of the periphery of the connector. Therefore, EMI noise may leak out by passing through a gap between the long side section of the plug housing and the long side section of the receptacle housing and through the long side section of the plug housing and the long side section of the receptacle housing.
There exists a need to address the aforementioned unresolved problems of conventional board-to-board connectors, in particular, to improve the EMI noise shielding performance of board-to-board connectors.